Prototype bean injection using type

Question

I am new to spring world. While learning about Prototype bean, I came across a weird response.

• I defined a bean with scope prototype

@Configuration
public class BeanConfiguration {

    @Bean
    @Scope(value = BeanDefinition.SCOPE_PROTOTYPE)
    public MessageService configureEmailMessageService() {
        return new EmailMessageService();
    }
}

• I am injecting the bean using Match By Type.

public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(BeanConfiguration.class);
        MessageService email = context.getBean(EmailMessageService.class);
        System.out.println(email.hashCode());
    }

While executing this, I am getting

No qualifying bean of type 'com.my.personal.project.spring.di.bean.services.EmailMessageService' available

But when I inject using name as shown below, it's working.

MessageService email = context.getBean("configureEmailMessageService");

My question is : Isn't it possible to inject prototype bean through Type ? Or am I missing something ?

Thanks

Answer 1

You are searching for a bean of type EmailMessageService, but in the BeanConfiguration class you are exposing a method that return a generic MessageService.

You need to get a bean (with the method getBean) that is a MessageService.class.

Try to change the signature of method

@Bean
@Scope(value = BeanDefinition.SCOPE_PROTOTYPE)
public MessageService configureEmailMessageService() {
    return new EmailMessageService();
}

to

@Bean
@Scope(value = BeanDefinition.SCOPE_PROTOTYPE)
public EmailMessageService configureEmailMessageService() {
    return new EmailMessageService();
}

or change the row

MessageService email = context.getBean(EmailMessageService.class);

in

MessageService email = context.getBean(MessageService.class);